Active Directory (AD) has sites, which you can use to group servers into containers that mirror your network’s physical topology. Sites also let you configure replication between domain controllers (DCs). In addition, you can map several TCP/IP subnets to sites so that new servers can automatically join the correct site depending on their IP address and so that clients can easily find the DC closest to them.

When you . . . → Read More: How to create a new Active Directory site?